1. Field of the Invention
The present invention relates generally to a device and method for transporting live finned fish, and more specifically to an improved truck mounted transport tank for transporting live catfish. While a primary market for the invention is live catfish transport, it can also easily be adapted for the transport of other aquatic species such as crabs, oysters, lobsters, shrimp, and the like.
2. Description of the Prior Art
As will be familiar to those skilled in the relevant industry, live fish in the United States have traditionally been transported over-the-road by “live haul” trucks. These are typically flatbed trucks that have been significantly modified to carry fish. Typical modifications include the permanent installation of one or more insulated fixed tanks or boxes in the flatbed. These tanks typically have hinged lids on the top and one or more circular or rectangular release gates on side of the tanks for simultaneously discharging water and fish. The earlier mechanical aerators using small motors and propellers have more recently given way to liquid oxygen tanks, manifolds carrying the gaseous oxygen to oxygen flow meters, and subsequently to aeration bubblers located in the bottoms of the tanks.
The standard live haul truck may be used for live bait hauling or fingerling stocking as well as for transporting live food fish. Due to the variety and types of loads, pickup and discharge locations, the configuration of these live haul trucks is far from standardized. Rather, the live haul truck is often a highly specialized, dedicated piece of equipment which is not intended for alternative uses. In ordinary practice, the fish are loaded dry (i.e., in nets without water), directly from the tanks and/or ponds of the fish farm into the integral fish tanks of the live haul truck.
Traditional live haul trucks which are commercially available in the industry include such companies as Seaplast PLC (Dalvik, Iceland), Seaplast Canada Ltd. (New Brunswick, Canada) and Peterson Fiberglass Laminates, Inc (Shell Lake, Wis.). These insulated tanks may be manufactured from a number of different materials including fiberglass, plastic, wood, and metal.
Just as in the case of fixed culture environments, such as containment ponds, tanks and aquariums, the transport tanks used on live haul trucks typically need an aeration system to supply sufficient oxygen to the aquatic livestock. Without an aeration apparatus in the aquatic environment, the livestock may die due to lack of oxygen. In addition to supplying oxygen, the aeration apparatus typically provides the additional advantage of achieving agitation of the bottom layers of the water to help prevent stagnation of the bottom portion of the aquatic environment. Agitation of the bottom of the aquatic environment also stirs up and redistributes the nutrients or food that have sunk to the bottom. The aquatic environment also requires a controlled circulation to prevent stagnant corners or regions.
One problem that exists at the present time is that the prior art tanks have tended to place the aeration lines on the bottom floor of the tank interior. The fins of the fish often damage the aeration lines, presenting a maintenance problem. In the case of routine maintenance, or an emergency situation, it was generally necessary to remove the fish and drain the tank in order to allow a worker to climb down into the interior of the tank to access the lines. In this regard, there is an obvious need to limit the handling, netting, moving by pump, draining via chutes, and otherwise touching of the live fish that would be required during such maintenance operations. Any time the fish are handled and moved, there is the chance of injury. Even careful handling of the fish can result in fungus and other type skin infections which are injurious to the fish.
Various aeration systems have been used in truck transport and other type systems in the past. For example, U.S. Pat. No. 6,557,492, shows a live fish transport system in the form of insulated tanks which can be used with live haul trucks. The tanks are made of polyethylene and may include “fork liftable” footed bases. As explained beginning at Col. 11, line 1, et seq., anchors 275 are adhered to the interior surface of the tank which serve as brackets for mounting the oxygen diffusers in position.
U.S. Pat. No. 3,401,671 shows a fish shipping container formed of an insulating material such as Styrofoam™. The bottom wall is provided with a grid 18 made up of lands 20 and channels 22. The channels provide air circulation to prevent conduction of heat from the container to floor of the freight compartment but are not used to house aeration conduits.
U.S. Pat. No. 5,606,935, shows a transportable fish tank including a mounting frame or base 120 and longitudinal base frame members 121. In one aspect of the disclosure, longitudinal recesses 48 are provided for inlet conduits, suction conduits and skimmer conduits (Col. 8, lines 12–14). These conduits are indicated as “I”, “SU”, and “SK” in FIGS. 2, 9 and 10. These exterior conduits are apparently connected to such devices as the skimmer assembly (65 in FIG. 6). The lower tube 67 passes upwardly through the tank wall and may be sealed with a sealing ring or gasket.
None of these prior art systems address the problem of making the aeration lines easily accessible from the tank exterior for routine maintenance type operations.
Therefore, there remains a need for an apparatus that adequately aerates the tank of a long haul truck which is easy to access for maintenance purposes.
There is also a need for such a device having an aeration apparatus which is located in a protected fashion relative to the live fish in the tank, so that the fins of the fish do not come into contact with the aeration lines themselves.
There is also a need for an improved method for maintaining oxygenation, providing bottom agitation and controlling circulation to an environment for aquatic livestock, such as a catfish transport truck.